Conventional fluid pressure operated railway freight car brake apparatus is fail-safe in operation in that an automatic brake application is effected on all cars in a train upon the loss of train brake pipe pressure as from, for example, a break-in-two of the train brake pipe.
In addition to the conventional fluid pressure operated brake apparatus, it is necessary that each freight car be provided with a hand brake which must be applied when the car is to be detached from a train for any appreciable period of time since the fluid pressure emergency brake application effected at the time the car is detached is released as the result of leakage of the fluid under pressure from the fluid pressure brake apparatus. A conventional hand brake apparatus embodies a chain and hand brake wheel whereby a trainman effects a hand brake application by the application of considerable manual force to this wheel. Accordingly, it has been found in actual practice that trainmen often times apply insufficient manual force to this hand brake wheel to cause the brake shoes to be pressed against the tread surface of the car wheels with the required degree of force necessary to insure that the car cannot be moved by a malicious person.
Furthermore, many times when a car is detached from a train, the trainmen are negligent in that no attempt is made to effect a hand brake application on the detached car. It is obvious that such a detached car is hazardous.
Accordingly, it is the general purpose of the present invention to provide a conventional fluid pressure operated automatic freight car brake apparatus with a novel brake cylinder having a hand brake applying spring and a release reservoir charged from the brake pipe by an air-driven air booster from which reservoir, or the train brake pipe, fluid under pressure may be supplied to the brake cylinder to compress the spring and thereby release the hand brake application.